Download CH 4956 - Loyola College

LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION - CHEMISTRY
FOURTH SEMESTER – APRIL 2011
CH 4956 - ADVANCED COORDINATION CHEMISTRY
Date : 09-04-2011
Time : 9:00 - 12:00
Dept. No.
Max. : 100 Marks
Part-A
Answer all questions. Each question carries two marks
1.
2.
Define an A-ET-E device.
How does change in the angular orientation of a ligand with respect to the metal ions affect the
magnitude of - and -bonding?
3. Give two examples of gadolinium-based contrast reagents for MRI.
4. Mention the prominent emission bands of europium(III) and terbium(III).
5. What are the different kinds of metallodendrimers.
6. How is the kinetic lability of alkali- and alkaline earth metal complexes of macrocycles exploited in
the synthesis of the corresponding transition metal complexes?
7. How do you convert complex of a ring contracted macrocycle into that of the ring expanded one?
8. Mention the causes of electrochemical irreversibility in the case of transition metal complexes.
9. Define quantum down-conversion.
10. Complexes of d10 metal ions are often spectroscopically silent. Comment
Part-B
Answer eight questions. Each question carries five marks
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
Illustrate a pH controlled molecular shuttle.
Construct a molecular break.
Explain the method of synthesizing dendrimers with examples.
Explain the synthesis of compartmental macrocyclic complexes by coordination template method
with examples.
Explain acid/base driven threading and dethreading motions in supramolecular assemblies.
-Back bonding by ligands increases the magnitudes of 10Dq values. Explain with a qualitative MO
energy level diagram.
What is cation-cavity “best fit”? Illustrate with examples.
Explain the electronic spectral features of low-spin transition metal ions in Oh and Td geometries.
Give a brief account of the photochemistry of lanthanides.
Explain the template synthesis of 2- and 3-catenanes.
Explain the principles of spectroelectrochemistry. Highlight the limitations of this technique.
Construct the Orgel diagram for high-spin d3 and d7 metal ions in Oh geometry. Explain the features
of their Tanabe-Sugano diagrams.
Part-C
Answer four questions. Each question carries ten marks
23a. Explain the EPR spectrum of bis(salicylaldimine)copper(II) and justify your interpretation with
experimental evidences.
(7)
b. What is zero field splitting? Mention its causes for transition metal complexes.
(3)
24. Explain the different synthetic strategies employed for symmetric and unsymmetric compartmental
macrocyclic ligands and their complexes.
25a. Explain the principle of angular overlap model.
(3)
b. With the help of angular overlap model show that t o


26a. Explain the principle and methodology of cyclic voltammetry.
b. The cyclic voltammogram of a dinuclear Cu(II)/Ni(II) complex consists of two cathodic waves at Epc
= -0.56 and -0.34 V and two anodic waves at Epa = -0.5 and
-0.25 V at the scan rate of 100
-1
mV s with ipc values of 25 and 19 A, and ipa values of 23 and 19 A. Compute the electrochemical
parameters and explain the electrochemical behavior of the system.
27a. Explain the principle and methodology of constructing a dye sensitized solar cell. (6)
b. Give an account of Ru(II) polypyridyl complexes used in the construction of solar cells.
(4)
28a. Mention the different kinds of rotaxanes.
(3)
b. Explain the construction of such assemblies by various synthetic methods.
(7)
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